BLADE WITH BUILT-IN COMPOSITE SPAR Russian patent published in 2015 - IPC B64C11/26 

FIELD: transport.

SUBSTANCE: invention relates to aircraft engineering, particularly, to turboprops and propellers. Blade (10) comprises structure with aerofoil (20) with two opposite skins (21, 22) produced by 3D braiding of fibrous reinforcing material (100), spar (30) containing fibrous reinforcing material produced by 3D braiding and compacted by female die. Said spar comprises first part (31) extending beyond said structure with aerofoil and can be engaged with driven hub at blade revolution, and second part located inside said structure between two skins (21, 22). Spar (30) second part (32) features depth, in fact, similar to that of skins (21, 22). Fibrous reinforcing material of spar (30) second part (32) has the same braided reinforcement like that of skins (21, 22). Method of blade fabrication comprises making of the first blank of skins and second fibrous spar blank by 3D braiding of threads. Second blank comprises first and second sections. Note here that second section features depth, in fact, equal to that of first blank skin and reinforcement identical to skin.

EFFECT: higher mechanical properties of blades composed of two parts.

18 cl, 20 dwg